the ways Chris suggested would suffice
if it's only the orbiting object you want to be moving then i would use the motion path approach
in the curves shelf you can create a nurbs circle
in the animation menu set you can find Animate>Motion Paths>Attach to motion path
for further information on motion paths refer to the Maya tutorial on it that came with Maya
that's a "Ch" pronounced as a "K"
Computer skills I should have:
Objective C, C#, Java, MEL. Python, C++, XML, JavaScript, XSLT, HTML, SQL, CSS, FXScript, Clips, SOAR, ActionScript, OpenGL, DirectX
Maya, XSI, Photoshop, AfterEffects, Motion, Illustrator, Flash, Swift3D